Crank shaft lapping machine



Jam. 3, 1933. A. J. s'I'RoNG cRANK SHAFT LAPPING MACHINE Filed May`24, 19.26

'2 Sheets-Sheev I I I I I I I I I LSQSM Jian. 3, 1933. A. J. STRONG CRANK SHAFT LAPPING MACHINE Filed May 24, 1926 '2 Sheets-Sheet lill Patented Jan. 3, 1933 STATES ARTHUR J'. STRONG, 0F DETROIT, MICHIGAN, ASSIGNOR T0 .NORTON COMPANY, OF WORCESTER, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS CRANE SHAFT LAPPING MACHINE Application illed May 24, 1926. Serial No. 111,271.

This invention relates to a crank shaft lapping machine, and an object of the invention is to simplify and cheapen the operation of lapping the crank pins and bearing parts of a multiple throw crank shaft, and to so apply the lapping means as to provide great accuracy and secure a smooth glass-like surface. A further object is to accurately regulate and facilitate the application of the lapping means to the shaft and with a ylelding pressure applied in a manner to eliminate vibration. and secure speed of operation. A further object is to provide an arrangement whereby the operation of lapping one or more of the parts may be continued or discontinued at will to give the desired relative finish to the several parts, and it is also an object to provide an automatically operating machine .for the purpose which is simple in construction and eiiicient in operation, and wherein are embodied certain other new and useful features.

With the above and other ends in view, the invention consists in applying lapping means simultaneously to the several' crank pins and bearing members of a multiple throw crank shaft with a yielding pressure, and rotating the shaft upon its longitudinal axis, with certain of said lapping means arranged to fol- 1 E3 low the crank pins during rotation.

The invention further consists in moving said shaft and lapping means relatively in a direction longitudinally lof the crank shaft during its rotation, and in providing a machine for the purpose which is simple in construction and efficient in operation, and which embodies other new and useful features in the construction and arrangement of parts, all as hereinafter described and more particularly pointed out in the appended claims, reference being had to the accompanying drawings, in which- Figure 1 is a side elevation of a machine illustrative of an embodiment of the invention and showing parts broken away and in section to more clearly disclose the construction;

i Fig. 2 is a transverse section of the same taken on the line II-II of Figure 1;

Fig. 3 is a plan view of an end portion of the machine, and

Fig. 4 is a sectional detail of a guide and support for one of the lapping-stone carrying arms, substantially upon the line IV- IV of Figure 2.

While a particular construction is shown in the accompanying drawings, it will be understood that the same is merely illustrative of an embodiment of the present in- 30 vention, and as shown, this machine comprises a suitable form of base or support 1 which is provided, upon its upper end ad- ]acent the forward side thereof, with a suitl able longitudinally extending guide-way 2 65 for a table or carriage 3, which carriage has a bearing head 4 at one end thereof through which head a drive shaft 5 extends. This shaft is provided with a drive pulley 6 upon its outer end, and at its inner end is formed wlth a conical centering or pointed end portion 7 to guide and center the work, and mounted upon the inner end of the shaft to turn freely thereon, is a sleeve 8 having an end flange 9 provided with pins 10 to engage 75 openings or bolt holes in the usual end fiange 11 on the end of a multiple throw crank sha-ft w2hich is indicated as a whole by the numeral A suitable clutch member indicated in dotted lines at 14 in Figure 1, is provided Within the head 4 to connect ythe sleeve 8 with the drive shaft and disconnect the same therefrom, said clutch being operated by a hand lever 15.

At the opposite end of the carriage 3 is a bearing head 16 within which is mounted a centering pin 17 having a tapered conical end to engage the end of the crank shaft 12 at its axis of rotation and support the crank shaft in a manner to permit it to rotate freely, the centering pin 17 being moved endwise in its y,bearings by means of a hand lever 18 in the usual Jmanner to engage the pin with the end of the shaft and disengage it therefrom when it is desired to remove the shaft from the machine.

Extending parallel with the guideway 2 longitudinally of the base 1 and at the rear side of the base, is a channel member 13 100 formed with a guide groove 13a in its upper side and a longitudinal slot in the bottom of the groove, and seated upon this channel member is a series of vertical guide brackets 19 and a series of bearing brackets 20.

Upon each of the ybearing brackets 2O is supportedv a lever or bar 21 which is pivoted at 22 intermediate its ends upon the bracket and at its forward end carries a retaining 10. member or pocket 23 for an abrading stone 24 which is curved at its upper side to conform to the curvature of the lower side of one of the bearing portions 25 of the crank shaft .12. There is one of these bearing brackets with its abrad'ing stone carrying arm positioned opposite each of the bearing portions of the crank shaft, and the abrading stone 24 is held in contact with the bearing portion bycrocking the arm upon its piv- ,20 otal support by means of a coil spring 26 connected to the rear end of the arm and attached at its lower end to the rearwardly projecting end of an arm 27 secured upon a rock shaft 28 journaled in bearings on the 25 base 1. The outer end of the rock shaft 28 is provided with a hand lever 29, and to hold this hand lever in adjusted position, a sector 30 is provided upon the end of the base to be engaged by a latch 31 carried by the lever.

30 -Adjustment of the hand lever 29 will therefore put a tension upon the several springs 26, thus rocking the arms 21A and bringing the stones 24 into yielding contact with the bearing portions 25 of the crank shaft. Upon rotation of the crank shaft, these bearing portions will be accurately lapped by the upward spring ypressure of the lapping stones against their surfaces.

Each of the several vertical guide brackets 19 has a plane vertical side face, and spaced from this face are bars 32 secured to the bracket by spacing studs 33a, thus providing an open vertical guideway between the face of each bracket and the bars 32,

for a rectangularbar 33, which bar at its forward end 'carries a stone holder or pocket member 34 within which an abrading stone 35 is detachably secured, said stone having a curved face to fit the curvature of one of the crank pins 36 of the crank shaft.

Each of the several bars 33 carrying the abrading stones 35 is supported within its vertical guideway on, its bracket 19 by means of an anti-friction hearing 37 which is secured to the face of each of the brackets 19 bar 33 positioned opposite each of the crankv pins 36 of the crank shaft and therefore all of the .crank pins are simultaneously lapped by the engagement of the several abrading of support upon the bearings 37. These springs 38 are attached at their lovver ends to arms correspondmg tothe arm 27 upon the rock shaft 28, so that tension may be put upon al1 of the springs 38 and all of the springs 26, at the same time and to the desired degree, by the operation of the hand lever 29.

To cause the stones 35 to cut evenly and smoothly, it is preferable that a suitable liquid, such for instance as kerosene, be supphed to the cutting surfaces of each of these several stones, and to so supply this liquid, a small hole 39-is drilled through the end of each bar 33 and through thecenter of the stone 35, and leading to this hole is a pipe 40 secured upon the upper side of the bar 33 and extending/longitudinally thereof, and to the rear end of this pipe is connected a flexible hose 41 leading to a supply pipe 42 mounted upon the rear side of the ase 1 and extending longitudinally thereof. The kerosene or other iu'id is supplied to the pipe 42 under pressure in the usual manner and flows therefrom through the several flexible tubes 41 to the several abrading stones, the lieXible tubes permitting a free and unrestricted movement of the bars 33. Kerosene is thus supplied in any desired quantity to lthe cutting surfaces of the several stones 35, all during the operation of the machine in lapping the several crank pins of the crank shaft.

After the lapping operation has been completed the rotation of the crank shaft is stopped by disengaging the clutch 14 and to permit the ready removal of the shaft from between its supporting centers 7 and-17, the several llapping' bars 33 are each lifted out of contact with its crank pin after the tension of` the springs 38 has been relieved by an operation of the hand lever 29, the operator grasping a handle 43 provided for the purpose upon the forward end of each of the bars 33, and to prevent these bars from falling to the bottom of their guideways, each bar is provided with a vhook 44 so that the operator may by'means of the handle 43 lift the forward ends of the bars to disengage the stones from the crank pins and then move the bars longitudinally and engage the hooks 44 with one of the studs 33a on the guide brackets 19. The several bars 33 are therefore supported in a position to be again readily manipulated by` the operator to bring the stones into engagement with v the crank pins of another crank shaft to be lapped. I

The lapping stones 24 are held 1n yieldmg engagement with the lower sides of the sevlac eral bearing portions of the crank shaft and exert an upward pressure upon the crank shaft, and the several stones 35 are yieldingly held in contact with the upper sides of the crank pins of the shaft and with a downward yielding pressure, so that these lapping pressures. are in opposed relation against the crank shaft, and vibration ofthe shaft is thereby eliminated. As the crank shaft is rotated, the stones 35 being held bythe springs 38 in yielding contact with the crank pins, the several bars 33, by reason of` such contact of the stones with the pins will cause the bars to move with the crank pins, following the path of rotation of the pins as the bars are free to move both longitudinally and vertically in their guides and are supported by the anti-friction bearings 37 so that there is a minimum of resistance to such movement of the bars.

In order to prevent'the several stones 24 and 35 from forming slight annular grooves in the surfaces to which they are applied by traveling in an exact path during the entire rotation of the crank shaft, the crank shaft and the several lapping members are moved relatively in a direction longitudinally of the shaftduring its rotation, and thus the path ofltravel of the stones in contact with the surface to be lapped is being constantly changed, giving a very smooth glass-like surface to the parts being lapped. To provide for such relative movement between crank shaftv and lapping members, each of the several lapping stones is slightly less in length than the length of the surface to be lapped thereby, s'o that the shaft may be moved slightly in a longitudinal direction without bringing the ends of the stones into contact with` the cheeks or surfaces of the shaft at the ends of the pins and bearing parts of the shaft, and to so move the crank shaft in a longitudinal direction during its rotation, means is provided for moving the carriage 3 longitudinally, said means comprising an eccentric pin 45 carried by a vertical shaft 4x6 mounted in a suitable bearing bracket a? within the base 1 below the carriage, and with this eccentric.' pin engaging a downwardly extending lug 48' on the carriage, rotation is impartedD to the shaft 46 by any suitable means such as gearing 49, from a horizontal shaft 50 extending through the end wall of the base and provided at its outer end witha pulley engaged by a belt 52, which belt also engages a pulley 53 on the outer end of the drive shaft 5. Therefore, motion is transmitted from the drive shaft 5 to rotate the vertical shaft 46 carrying the eccentric pin 45 which will by its ecoentricity-impart a longitudinal vibratory motion to the carriage 3 and thus move the crank shaft longitudinally during its rotation. Great accuracy in the lapping operation is therefore secured and a glass-like surface is formed faces in Contact with the stones and the relative longitudinal movement between the stones and surfaces.

It is obvious that a crank shaft having any desired number of cranks and pins may be lapped by the use of a machine of the character described, it being only necessary to increase the length of the machine to take care of crank shafts of greater lengths, and crank shafts of different designs and construction may be lapped, as the several guide brackets 19 and bearing brackets 20 are readily adjustable along the channel members 17 to give the proper spacing of the several lapping members.

With a machine embodying the present invention, the several bearing portions and crank pins of a crank shaft may be simultaneously lapped and with eat accuracy and smoothness of surface iiish, and the relative surface finish of the several pins and bearing parts may be accurately controlled, as one or more of the lapping members may be thrown into or out of contact with the surface lbeing lapped, as desired.

Obviously the form of the lapping stones and arrangement thereof may be varied according to the work in hand, and other changes in the construction, arrangement and operation of parts may be made within the scope of the appended claims without departing from the present invention.

Having thus fully described my invention, what l claim is 1. A machine of the character described for dressing a crank pin of a crank shaft, including means for rotating said shaft upon the axis of its bearing portion, means engaging the surface of the crank pin for removing metal therefrom, said means being sup- .ported partly on the crank pin and partly on a support upon which it is guided and partly supported for movement with the crank pin in its path of movement about said axis of rotation,means for moving said crank shaft and saidengaging means, one relatively to the other in a direction longitudinally of the shaft, and means for resiliently holding said engaging means in contact with said pin and said guiding and supporting means during rotationof the shaft.

2. A lapping machine for simultaneously lapping all of the crank pins of a multiple throw crank shaft including means for supporting a crank shaft and rotating the same upon its normal axis of rotation, lapping means engaging a portion only of each of said crank pins, so as to permit relative longitudinal movement of said shaft and supporting means during rotation of the shaft and permit movement away therefrom to allow escape of detritus, carrying members for carrying said lapping means and movable with the crank pins in their path of movement about said axis of rotation, a support upon which sai-d carrying members may rock and slide, means for yieldingly holding said carrying members with said lapping means in contact with said pins and said support, and means for moving said crank shaft and the several lapping means one relatively to the other in a direction longitudinally of the crank shaft" during its rotation.

3. In a machine of the character described, the combination of means for supporting and rotating a crank shaft, a plurality of guide brackets arranged in spaced relation adjacent the crank shaft and providing vertically extending open guideways, carrying members within said guideways of said brackets for carrying lapping instrumentalities and free to move longitudinally and vertically therein, and means for holding said members with said instrumentalities carried thereby in yielding contact with the several crank pins of the crank shaft and with a"support provided therefor upon which said members may freely rock and slide endwise as they pivot on the crank pins in their travel.

4. A lapping machine as characterized in claim 3, and wherein said guide brackets are normally fixed against movement longitudinally ofthe crank shaft, and means is provided for reciprocating said shaft longitudinally.

5. In a machine of the character described, the combination of a supporting base, means adjacent the ends of said base to engage the ends of a crank shaft and support and center the same, means for rotating the crank shaft while so supported, means for reciprocating the crank shaft longitudinally, a plurality of normally fixed vertical guides carried by the base and arranged along the shaft at one side thereof, bars free at yone end to follow the rotative movement of the cranks of said crank shaft and pivotally supported for longitudinal and vertical movement in said vertical guides, lapping instrumentalities carried bysaid bars in engagement with the crank pins of the crank shaft to move in circular paths therewith, and yielding means for holding said bars with said instrumentalities ycarried thereby in contact with said crank pins.

6. A machine as characterized in claim 5, and including lappin instrumentality carrying members pivota y supported upon the base and provided with lapping instrumentalities, and means for yieldingly holding said members with said instrumentalities in con.- tact with the lower sides of bearing portions of the crankshaft, and in opposed relation) to the engagement of said instrumentalities on saidl bars with said crank pins. 7 L In` alapping machine, ,the-cpfmb with vmeansffor supportngjn-a nation?. l'iyield'ing mea' its ends and rotating and reciprocatin the same, of lapping means yieldingly he d in contact with the lower sides of bearing portions of the crank shaft, a plurality of lapping members movable into and out of en-j vertical movement with the crank pins during rotation of the crank shaft.

8.- In a lapping machine, the combination of a supporting base, a carriage reciprocable upon the said base, means on the carriage for engaging and centering the ends of a crank shaft, means for rotating the crank shaft while so supported, means for reciprocating the carriage during rotation of the crank shaft, a plurality of guide brackets adjustably supported upon the base and arranged along the carriage, said brackets forming open vertical guideways, bars guidedin said guideways, anti-friction bearings on the brackets to engage the lower sides of the bars, lapping stones carried by the forward ends of the bars to engage the crank pins of the crank shaft, a series of levers pivotally supported upon the base intermediate their end's, lapping stones carried by the forward ends of said levers to engage the bearing portions of the crank shaft from beneath the same, springs connected to said bars between forward ends and their supports upon said antifriction bearings, springs connected to the rear ends of the pivoted levers, and hand operated means to which all of the said springs are connected at their lower ends for lacing said springs under tension and releasing the same.

9. In a machine for simultaneously finishing all of the crank pins and bearing members of a multiple throw crank shaft, including means for supporting the shaft at its ends and rotating the same upon the axis of l its bearing members, carrying members, a support upon which said carrying members may rock and slide, lapping members mounted upon .one` end of said carrying members to engage one side of the several crank` pins, means for yieldingly holding said lapping members in contact with said crank pinsand having a point of reaction against a fixed part of the machine, said yielding means permitting bodily movementof said lapping meml bers to disengagefthefsame from saidfpins, carrying members having means .for engagmembers' ing ahjs'idefof said bearing` -members'jof 'the' `shaft vfor .removal 1 of metal '.therefrom, and

for. movingsaidlfcarrying ,t v

Y said-',inetali removing means; 130 f the crank pin while maintaining its working engagement therewith.

l1. In a lapping machine, the combination of means for supporting and rotating a crank shaft, lapping means, a carrying member for said lapping means mounted to follow thel revolution of the crank pin and to prevent rosaid pin, a guide adjacent the path of movement of the crank pin, through which guide said member moves endwise inits path of movement following the crank pin for conlining sai-d member in its movement to a plane normal to said shaft, and means for causing relative movement between said shaft and carrying member axially of the shaft during rotation thereof.

12. Means for supporting and rotating a crank shaft, lapping means, carrying members therefor, means for mounting said members so that the lapping means may follow the revolution of the crank pins but be prevented from rotating circumferentially of said crank pins, guides adjacent the paths of movements of the crank pins and between the said means for mounting the members and the crank shaft supporting means and through which guides said members move endwise in their motion derived vfrom the crank pins for confining said members in their movements to planes normal to said shaft in which said members move, and means for causing relative movement between said shaft, and said lapping means and members in a direction axially of the shaft and during rotating thereof.

13. A lapping machine for simultaneously lapping all ofthe crank pins of a multiple throw crank shaft including means for supporting a shaft and rotating the same upon its normal axis of rotation, lapping means en gagin each of said crank pins, carrying members or carrying said lapping means and movable with the crank pins in their path of movement about said axis of rotation, means for yieldingly holdingsaid carrying members with said lapping means in contact with .60 said pins, stationary means adjacent the paths of movement of the crank pins for preventing lateral movement of said carrying members and for guiding the same during reciprocative movement thereof .in following the paths 65 of movement of said crank pins, and means tation of said members circumferentially of,

for moving said crank shaft and the several .carrying members, one relatively to the other 1n a` direction longitudinally of the crank shaft during its rotation.

In testimony whereof I aiiix my signature.

ARTHUR J. STRONG. 

